The unitary executive theory is a theory of United States constitutional law which holds that the President of the United States possesses the power to control the entire federal executive branch. The doctrine is rooted in Article Two of the United States Constitution, which vests "the executive power" of the United States in the President.Although that general principle is widely accepted ...

Properties. For any unitary matrix U of finite size, the following hold: . Given two complex vectors x and y, multiplication by U preserves their inner product; that is, Ux, Uy = x, y .; U is normal (=).; U is diagonalizable; that is, U is unitarily similar to a diagonal matrix, as a consequence of the spectral theorem.Thus, U has a decomposition of the form =, where V is unitary, and D is ...